770-5m-16 Wheel drive belt For ScootR-R3, and Tiger scooters. Also for scooters with 79 tooth wheel sprocket after upgrading to ScootR Swingarms for using 10-10&1/2 inch rear tire. If R5 or FX or Star II, or THX PRO , possible correct belt is the 740-5m-15 or 740-5m-16